Method of manufacturing nonmetallic gear wheel blanks and the like



April 23, 1-935. c. w. MANsUR METHOD OF' MANUFACTURINGNONMETALLIC GEAR WHEEL BLANKS AND THE LIKE Filed May 21, 1930 2 Sheets-Sheet 2 Ivehtor:

Clarece W Mahsur, b5

I-Iis Attohe.

Patented Apr. 23, 1935 UNITED STATES METHOD OF MANUFACTURING NONMETAL- LIC GEAR WHEEL BLANKSAND THE LIKE Clarence W. Mansur, Malden, Mass., assigner to General Electric Company,

New York a corporation of Application May 21, 1930, Serial No. 454,464

' 4 Claims.

The present invention relates to the manufacture of bodies such as gear wheel blanks and the like, from a number of dissimilar elements formed from spinnable textile fibers treated with an uncured adhesive, such as a phenolic condensation product which is converted into its hard infusible state upon the application of heat and pressure.

The object of my invention is to provide an improved method of manufacturing such bodies, the advantages of which are pointed out hereinafter, and for a consideration of what I believe to be novel and my invention, attention is directed to the following specification and to the claims appended thereto.

My improved method is especially well adapted for use in the manufacture of blanks for nonmetallic gear wheels, and accordingly I have chosen to illustrate and describe the method as applied to this use. It is to be understood, however, that the invention is not limited thereto necessarily.

In the drawings, Figs. 1, 2, 3 and 4 are sectional views illustrating steps utilized in carrying out my invention; Fig. 5 is a perspective view of a completed gear wheel blank made in accordance with the method; Figs. 6, 7 and 8 are sectional views similar to Figs. l to 4 illustrating a modification of the invention, and Fig. 9 is a perspective view of a completed gear wheel blank made in accordance with the modified method illustrated in Figs. 6 to 8.

In Figs. l to 4 I have shown my improved method applied to the manufacture of a non-metallic gear wheel blank wherein the blankfis formed lfrom a number of pieces of woven textile material previously treated with an adhesive and cut to provide parts for forming the hub, web and rim of the blank. According to my invention, I provide an annular metal container I formed of relatively thin material so that it is light and easy to handle and provided preferably with a number of spaced openings 2`for the admission of steam or hot gases to the interior of the container. 'I'he container I is open at both ends and is of a diameter corresponding to that of the gear wheel blank to be made. For use with the container I provide a supporting ring 3 which may be made of any suitable material and which ts loosely in the bottom of the container,

In carrying out my invention, I rst place a container I with a ring 3 in the bottom thereof on a support or table 4, and I vassemble in the container I the several dissimilar elements which are to be utilized in forming the gear wheel blank. In the present instance the elements are shown as comprising pre-formed end sheets 5, intermediate sheets 6, rings 1 which form a part of the rim of the blank and a filling member 8 which forms the thickened portion of the hub. It is to be understood that the elements which 5 go to make up the gear wheel blank illustrated are shown only by way of example and are to be taken as typical of any suitable elements which are to be utilized in the manufacture of the gear wheel. 'Ihe container I is of a size such that the several elements fit in it with sufcient tightness that they are readily held therein. The ring 3 serves simply to keep the parts from being assembled in contact with the support 4 and so that they are held spaced from the lower end of the container.

After the elements are assembled in the container I, the container is placed in a suitable heating oven and heated, the oven preferably containing a moist atmosphere. For this purpose I may heat the elementsby means of steam, the steam providing the moist atmosphere, or I may utilize with advantage an electrically heated oven, the moist atmosphere being obtained by injecting steam into the oven. The arrangement may be such that the container passes through the oven on an endless carrier entering at an admission opening and coming out at a discharge opening. I have found that heating for a time of the order of six minutes and at a temperature of the order of 100 to 150 C. satisfactory. By heating the material in this way and preferably in the presence of a moist atmosphere, the adhesive is rendered plastic enough to stick the elements together without, however, curing to 35 any great extent the adhesive and without its becoming sticky enough to stick to a mold.

I consider the heating of the material in a moist atmosphere as being one important feature of my invention for by so heating the material 40 I find that a uniform temperature throughout the mass is obtained and that the presence of the moisture prevents the material from sticking to the mold used in making the preform.

After the preliminary heating,'the container I with the elements therein is lifted off the ring 3 and placed in a forming mold and pressed therein to produce a preform. By a preform I mean a body having the general shape of the iinished gear wheel blank and stuck together so that it can be handled as a unit, the resin however not being cured to any appreciable extent. The adhesive serves to stick the elements together and hold them. For this initial pressing operation I have found a pressure of the order of 2,000

pounds per `square inch satisfactory. In Figs. 2 and 3, 9 indicates the outer wall or shell of the forming mold, I 0 indicates the lower mold member, the upper surface of which is shaped as is indicated at II to the correct contour for forming the blank, and I2 indicates the upper mold member, the lower 'face I3 of which is shaped to cooperate with the face II on the lower mold member to give the desired contour to the blank. 'Ihe wall 9 has`a circumferentially extending opening I4 in itsupper portion through which the container I may be inserted into the mold, and an annular shoulder I 5 upon which the container I rests. The container is placed in the mold as shown in Fig. 2, after which the upper and lower mold members I2 and I0 are brought together to the position shown in Fig. 3. The mold forms, in substance, a permanent part of a suitable press such as an hydraulic press, being fastened' in the press in any suitable manner. The press and the detail arrangement for 'operating the parts of the mold are not illustrated as this forms no part of my present invention. Any suitable structure of press may be used. The upper mold member I2 forces the elements which go to make up the gear wheel blank out of the container I and such elements are compressed in the mold to provide a preform, as is indicated at I6 in Fig. 3. The preform I6 is then removed from the mold. The elements of the preform as thus compressed are thoroughly stuck together by theadhesive so that the preform may be handled as a unit and the preform has the general contour of the completed gear wheel blank, but at this time the adhesive is cured to only a slight extent. 'I'he preform I6 is now ready for its final pressing to shape and the complete curing of the adhesive. This may be done immediately after it comes from the preforming mold or it may be done at any other suitable time as is found convenient in the process of manufacture.

When the preform is to be given its flnal molding operation, it is first warmed to remove any moisture which may have been left in it or which it may have absorbed from the atmosphere, and to render the adhesive plastic. To accomplish this result, I have found that it is desirable to warm the preform for about twenty minutes in an oven at a temperature of the order of to C. 'I'he preform is then placed in a finishing or final mold and heat and pressure applied to bring the preform to its final shape and cure the adhesive. steam heated mold located in a suitable hydraulic press. Such a mold is indicated diagrammatically in Fig. 4 wherein I1 indicates the lower member of the mold and I8 the upper member of the mold. The construction and arrangement of the mold and the parts of the press are not illustrated in detail, since the specific structure forms no part of the present invention and since any suitable type ofA heated mold to which pressure may be applied may be utilized. Such molds are well known in connection with the manufacture of devices of the character described. 1

I nd it advantageous to initially heat the preform so as to render the adhesive slightly plastic before it is placed in the finishing or final mold, for this insures that as soon as the molds are brought together the material of the preform will flow readily so as to assume the shape of and completely fill the mold. This avoids the forming of pockets into which adhesive can ow.

For the nal molding operation I have found For this purpose I may use a a pressure of the order of 2,000 to 3,000 pounds per square inch and a temperature of the order of to 170 C. satisfactory, the pressing and heating taking place for a time of the order of twenty to forty minutes.

After the nal pressing and heating operation in the nishing or final mold, the finished blank is removed and is ready for use. A finished blank is shown in Fig. 5 wherein I9 indicates the hub, 20 indicates the web and 2! indicates the rim.

In Figs. 6 to 8 inclusive, I have shown a modified form of my invention for use when the gear wheel blank is to comprise a rim made up of rings formed from woven textile material, and a web and hub formed from a material such as loose cotton treated with an adhesive.

In Fig. 6, 22 indicates a container corresponding to the container I of Fig. 1, the container being of a size Ato hold the material 23 which is to form thehubfand web of the gear wheel blank. The material 23 is first weighed or measured and placed in the container 22 after which the ring or rings 24 which are to form the rim of the blank are placed on top of the container as shown. The container is then placed in a warming oven and the material heated in a moist atmosphere after the manner already described. After being heated it is then placed in the forming mold and given an initial pressing to provide the preform. The forming mold is illustrated diagrammatically in Fig. '7 wherein 25 indicates the casing or shell of `the mold, 26 indicates the lower mold member and 21 and 28 indicate the upper mold member which is made in two parts, part 21 being of a size to compress the rim of the blank and the part 28 being of a-size to compress the web and hub of the blank. The elements 23 and 24 are placed in the mold as is indicated in Fig. 7, after which the mold is closed as shown in Fig. 8 to compress the elements 23 and 24 to produce the preform 29. 'I'his operation may be carried out after a manner corresponding to that already described in connection with Figs. 2 and 3 of the drawings. The preform is then removed from 'the forming mold and is ready for the final pressing and curing operation which may be carried out after the manner described in connection with Fig. 4 of the drawings. Fig. 9 shows a completed gear wheel blank constructed in accordance with the modification illustrated in Figs. 6 to 8.

By my improved method I effect a reduction in the labor cost of handling parts during the process of manufacture. By the former method utilizing hand molds, that is, separate molds in which the elements forming the gear wheel were assembled, it was necessary for the workmen to handle these molds in assembling the elements therein, in putting the molds in Ithe press, and in removing the molds from the press and the finished gear wheels from the molds. In one instance, the double hand molds used weighed forty-five pounds each, which meant the handling, in the course of an eight-hour shift, a total weight of the order of twenty-five tons of steel. By the new method, the workman has to handle only the thin sheet metal containers in which the gear wheel elements ar'e initially assembled, for as will be clear, in this case the mold forms, in substance, a part of the press as distinguished from being a separate unit which is inserted in a press. application of my invention in one instance has reduced the direct labor cost by an amount of the order of twelve percent over a former hand mold method of manufacture. At the same time, I have found that the use of molds which in substance forma part of the press, is not more expensive than the former hand molds.

My invention has a further advantage in that it provides for a visual inspection of each gear wheel during the process of manufacture, that is, a visual inspection of the preform, a thing not provided for in the case of hand molds. By a visual inspection of the preform, any defects due to the assembling of the elements may be corrected if such as to permit of correction, or if not, then the preform may be discarded, thus avoiding the complete manufacture of a defective gear wheel blank.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. The method of manufacturing bodies comprising a number of dissimilar elements formed from spnnable textile fibers treated with uncured adhesive binder, which elements are to be assembled to form an irregular shaped body hav- `ing thick and thin portions, which comprises assembling the elements in a relatively light weight container and subjecting them to an initial heating to soften. the adhesive, placing the elements in a forming mold in definite relation to give the desired shape and compressing them to cause the elements to adhere but without curing the adhesive, thereby providing a prefrom, and finally placing the preform in a mold and applying pressure and heat to bring the preform to its final shape and cure the adhesive.

2. The method of manufacturing bodies comprising a number of dissimilar elements formed from spinnable textile fibers treated with uncured adhesive binder, which elements are to be assembled to form an irregularshaped bo@ having thick and thin portions, which comprises giving the elements an initial heating in the presence of steam to soften the adhesive, placing the elements in a forming mold in definite relation to give the desired shape and compressing them to cause them to adhere but without curing the adhesive. lthereby providing la preform, and finally placing the preform in a mold and applying heat and pressure to bring the preform to its final shape and cure the adhesive.

' the elements therein, transferring the assembled parts from such container to a preforming mold and subjecting the parts to pressure to provide a preform, and placing the preform in a final mold and applying pressure and heat to consolidate the structure and cure the adhesive.

4. The method of manufacturing bodies comprising a rim element and a rim connecting web element formed of spnnable textile bres treated with uncured adhesive binder, which elements are to be assembled to form an irregularly shaped body having a thick rim portion and a relatively thin web portion, which comprises assembling all the elements in the desired positions relatively .to each other in a preforming mold and subjecting them to heat and pressure in such mold to soften the adhesive and stick the several elements together to provide a preform, removing the preform as a unit from the preforming mold and placing the preform in a finishing mold and subjecting it to heat and pressure to bring the preform to its final shape and cure the adhesive.

CLARENCE W. MANsUR. 40 

